SmoothZoom.scm

; Plug-in:      SmoothZoom
; Author:		A2va
; Version:      1.0
; Date:         28.02.2020
; Tested with:  GIMP 2.10

;This program is free software: you can redistribute it and/or modify
;it under the terms of the GNU General Public License as published by
;the Free Software Foundation, either version 3 of the License, or
;(at your option) any later version.

;This program is distributed in the hope that it will be useful,
;but WITHOUT ANY WARRANTY; without even the implied warranty of
;MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;GNU General Public License for more details.

;You should have received a copy of the GNU General Public License
;along with this program.  If not, see <https://www.gnu.org/licenses/>. 1

;Install
;Open the Gimp user directory. 
;On Windows it is this path C:\Users\Username\AppData\Roaming\GIMP\2.10\script. 
;and copy the script file

;Use this script file OR the Scheme file but not both
(define (smooth_zoom_video_editing image drawable)

	(let* (
		(width (car (gimp-drawable-width drawable)))
		(height (car (gimp-drawable-height drawable)))
		(layer0 (car (gimp-layer-copy drawable FALSE)))
		(layer1 (car (gimp-layer-copy drawable FALSE)))
		(layer2 (car (gimp-layer-copy drawable FALSE)))
		(layer3 (car (gimp-layer-copy drawable FALSE)))
		(layer4 (car (gimp-layer-copy drawable FALSE)))
		(layer5 (car (gimp-layer-copy drawable FALSE)))
		(layer6 (car (gimp-layer-copy drawable FALSE)))
		(layer7 (car (gimp-layer-copy drawable FALSE)))
		(width_new 0)
		(height_new 0)
		(offsetX 0)
		(offsetY 0)
		)

	;Determine the width and height of image
	;and the offset on X and Y
	(set! width_new (* width 1.5))
	(set! height_new (* height 1.5))
	(set! offsetX (/ width 4))
	(set! offsetY (/ height 4))
	(gimp-image-resize image width_new height_new offsetX offsetY)
	;Create 8 layers
	(gimp-item-set-name layer0 "0")
	(gimp-image-insert-layer image layer0 0 0)
	(gimp-item-set-name layer1 "1")
	(gimp-image-insert-layer image layer1 0 0)
	(gimp-item-set-name layer2 "2")
	(gimp-image-insert-layer image layer2 0 0)
	(gimp-item-set-name layer3 "3")
	(gimp-image-insert-layer image layer3 0 0)
	(gimp-item-set-name layer4 "4")
	(gimp-image-insert-layer image layer4 0 0)
	(gimp-item-set-name layer5 "5")
	(gimp-image-insert-layer image layer5 0 0)
	(gimp-item-set-name layer6 "6")
	(gimp-image-insert-layer image layer6 0 0)
	(gimp-item-set-name layer7 "7")
	(gimp-image-insert-layer image layer7 0 0)
	
	;Move the layer
	(gimp-layer-translate layer0 (- width_new offsetX) offsetY)
	;Layer1
	(gimp-layer-translate layer1 (- ( / width_new 2)) offsetY)
	;Layer2
	(gimp-layer-translate layer2 (- width_new offsetX) ( - offsetY height))
	;Layer3
	(gimp-layer-translate layer3 (- ( / width_new 2)) ( - offsetY height))
	;Layer4
	(gimp-layer-translate layer4 (- width_new offsetX) ( - height_new offsetY))
	;Layer5
	(gimp-layer-translate layer5 (- ( / width_new 2)) ( - height_new offsetY))
	;Layer6
	(gimp-layer-translate layer6 offsetX ( - offsetY height))
	;Layer7
	(gimp-layer-translate layer7 offsetX ( + offsetY height))
	
	(gimp-displays-flush)
	
	)
)

(script-fu-register "smooth_zoom_video_editing"
    "Smooth Zoom"
    "That create a image for a smooth zoom transition"
    "A2va"
    "A2va"
    "28.02.2020"
    ""
    SF-IMAGE    "Image"         0
    SF-DRAWABLE "Layer" 		0
)

(script-fu-menu-register "smooth_zoom_video_editing"
                         "<Image>/Filters")